A287578 Positions of 1 in A287576.

4, 5, 10, 15, 19, 24, 25, 30, 34, 39, 44, 45, 49, 54, 59, 64, 65, 70, 75, 80, 84, 85, 90, 95, 99, 104, 105, 110, 114, 119, 124, 125, 130, 135, 140, 141, 145, 150, 155, 160, 164, 165, 170, 175, 179, 184, 185, 190, 195, 200, 201, 206, 210, 215, 220, 221, 225

Offset: 1

Author

Clark Kimberling, Jun 01 2017

Keywords

• nonn
• easy

Comments

a(n) - a(n-1) is in {1,4,5} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 0, 3, 2, 1, 1, 0, 3, 2, 2, 1, 0, 3, 3, 2, 1, 0, 3, 2, 1, 0, with

0 in positions given by A287577,

1 in positions given by A287578,

2 in positions given by A287579,

3 in positions given by A287580.

Links

• Clark Kimberling, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A287576, A287577, A287579, A287580.

Programs

Mathematica

s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9];   (* A287576 *)
Flatten[Position[s, 0]]; (* A287577 *)
Flatten[Position[s, 1]]; (* A287578 *)
Flatten[Position[s, 2]]; (* A287579 *)
Flatten[Position[s, 3]]; (* A287580 *)

Formula

a(n) = 4n - A287576(n) for n >= 1.